A problem to tackle: 49ers aim to fix fundamentals before facing Lynch

After failing their tackling test in Week 1, the 49ers will face a beastly exam Sunday night when they meet a noted nemesis, Seahawks running back Marshawn Lynch.

Lynch, 5-foot-11 and 215 pounds, is one of the NFL’s more capable tackle-breaking machines. Last year, he broke free from 63 tackles, ranking fourth in the NFL, according to Pro Football Focus, and continued his brilliance against the 49ers.

Lynch has had three straight 100-yard games against San Francisco, dating to Week 16 of the 2012 season. During that span, the 49ers have allowed just two 100-yard rushers in their other 21 games.

“He’s obviously a very hard guy to tackle,” defensive coordinator Vic Fangio said. “I know our guys have a tremendous amount of respect for him. He runs the ball extremely hard. And he’s got that misdirection and cutting and slashing ability that’s a little unusual for a guy his size. So any arm tackle or non-full-bodied-up tackle, he can run through. We’re going to have to guys swarming to make the tackles easier for all of us.”

According to Pro Football Focus, the 49ers missed seven tackles Sunday. Last year, they averaged 3.5 missed tackles a game.

Now, they’ll face Lynch, who has rushed for over 100 yards in 16 of his past 26 games. Last year, Lynch averaged 4.8 yards a carry against San Francisco, which allowed 3.6 yards a rush to the rest of the NFL.

Fangio clearly shares his players’ respect for Lynch. Asked which running back Lynch reminded him of, Fangio mentioned the NFL’s all-time leading rusher.

“Maybe Emmitt Smith, because Emmitt ran with power, and elusiveness and slashing-type running without great speed,” Fangio said. “That would be the one guy that came to mind.”

Including the playoffs, the 49ers have allowed nine 100-yard rushers in their past 84 games dating to Sept. 21, 2008. Lynch, who has faced the 49ers six times in his career, has accounted for four of those 100-yard games.